Geography of surnames in the Azores: Specificity and spatial distribution analysis

Abstract

In order to obtain a better understanding of the genetic structure of the Azorean population, a specificity and spatial distribution analysis was performed, based on 2,454 different surnames present in the Azorean telephone directory (2002). We considered as specific surnames those with an absolute frequency ratio equal to or higher than 50%. The results revealed 51 specific surnames in the whole archipelago. The smallest island presents the only surname with 100% specificity (Pedras). In addition, São Miguel island, which contains 54% of the Azorean population, has the highest number of specific surnames (25 specific surnames). The spatial distribution analysis was used to detect genetic similarity between municipalities through the calculation of spatial autocorrelation (Moran's I coefficient). Of 240 surnames included in the analysis, 113 showed statistically significant patterns. Five different patterns were obtained, of which the most relevant was isolation by distance and depression (41.6%). However, 43.4% had no defined pattern. The overall correlogram shows a majority of positive values for distances lower than 49 km and between 269-309 km, indicating high similarity between closer municipalities and between distant municipalities whose populations show historic and sociocultural affinities. In conclusion, our data are in agreement with the historical background of the Azorean population.

Testing Hierarchical Levels of Population Sub-Structuring: The Azores Islands (Portugal) as a Case Study

“…Maria, Graciosa and Corvo. 5) and that this last variable has an important impact on the genetic structure of the archipelago, which is in accordance with the spatial autocorrelation analysis results obtained by Cabral et al (2005) using data of surnames from the nine Azorean islands. 4) provide a similar picture with the islands of Sta.…”

“…The application of Malécot's model (Malécot, 1948) reveals that about 33% of the variation in kinship is explained by geographic distance (Fig. 5) and that this last variable has an important impact on the genetic structure of the archipelago, which is in accordance with the spatial autocorrelation analysis results obtained by Cabral et al (2005) using data of surnames from the nine Azorean islands.…”

Human DNA bank in Sao Miguel Island (Azores): A resource for genetic diversity studies

“…To date, this DNA bank was used to assess the Y-chromosome phylogeny and diversity in Azorean population [4]. Now, we are analysing autosomal STRs for the better understanding of the gene pool and genetic structure of the archipelago's population [5][6][7].…”

A study of the spatial distribution characteristics of Chinese surnames

“…Besides the visual presentation of spatial distribution of surname on map, most researches adopt spatial autocorrelation coefficient or spatial correlogram. Such analytical methods have been widely applied to various countries and regions to uncover classical patterns of population migration and diffusion, including England and Wales (Sokal et al, 1992), the Lecco area (Caravello & Tasso, 1999), the Azores (Cabral et al, 2005), the Portuguese-Spanish Border (Rom an-Busto et al, 2013), and Sardinia (Orrù et al, 2018).…”